Automatic gear shift



May 16, 1933.

J. c. STAFFORD AUTOMATIC GEAR SHIFT v Filed Feb. 8, 1932 J02; asz yom INVENTOR ATTORNEYS PM May 16,1933

UNITE-D STATES :omr oer-moan, or u'aarvnna, 'rnmm ssm LUTOIA'I'IG em sm'r Application fled February 8, 1988. Ho. 591,788.

The invention relates to an automatic pointed' out in the claims. hereunto aptransmi'ssion and more especially to an auto matic gear shift for use in motor driven ve- 'hicles. w p w 5 The'primary object of th invention is the provision of mechanism offithis' character wherein speed changes from ow to high or vice versa is automatically eifected thus eliminating the .usual manual shifting of the power transmission gearingfor this purpose as enerally employed in motor drlven vehic es and in this manner relieving attention on the part of'an operator of such vehicle. I

Another object of the invention is the pro: vision of mechanism of this character, wherein the s eedfrom a driving shaft to a driven sha ft can be transmitted in a smooth and uniform manner by the useof a planetary gear assembly, an overrun clutch and a ball governor controlled friction clutch, thus ellminating the manual control of a shift lever by an o erator for speed changes between low and igh or vice versa, the speed changing being automatically taken care of throu h the mstrumentalities mentioned and therehy obviating faulty gear changing with resultant damage to the gearing and close attention of an operator as is essential in the hand shift speed changing transmission gearing. v

A further object of the invention is the. provision: ofmechanism of this character,

which'is' comparatively sim le in construction thoroughly reliable an eflicient in operation,com act, strong, durable, automati-' cally contro able, and inexpensive to manufacture'and install. K

a With these ahd'other objects in view, thee invention consists in the features of con:

'struction, combination and arrangement of parts as will be hereinafter more fully described in detail, illustrated in the accomanying drawing,"which discloses the preerred embodiment of the invention, and

pended.

In the drawing F1 ure 1 is a vertical longitudinal sectiona view through the-mechanism con- 'structed in accordance with the invention.

Figure 2 is a sectional view on the line- 2--2 of Figure 1 looking in the direction of the arrows;

Figure 3, is a sectional view on the line 33.of Figure 1.- l x Si 'lar reference characters indicate corresponding "parts throughout the several.

.views in the drawing. p Referring to the drawing in detail, A designates generally a ortion of the driving shaft A of a motor, or example, the en 'ne' of a motor driven vehicleand B the drlven shaft thereof, the latter havin a socket 10 for the reduced extension 11 o the driving shaftAso that these shafts will be loosely interfitted witheach other internally of a casing or housing 12 for accommodating the speed changing mechanism or automatic transmission hereinafter fully described.

The casing 12 is preferably made of separable sections suitably detachably joined mesh with the sun gear 18-having a', sleeve hub 19 loosely journaled upon the driving shaft A while encircling said; sleeve 19 is an overrun clutch gear 20, the lattermeshtrically disposed slots 23 in an overrun clutch member 24 fixed in a supporting web 25 therefor formed in the casing 12.

Fixed to the sleeve hub 19 is a separator disk 26 of a friction .clutch which includes a cylindrical enclosing shell 27 having the separator disk 26 sphned or keyed as at 28 therewith. Arranged on opposite sides of the separator disk 26 and confined within the shell 27 are the series of clutch rings or clutch plates 29 and 30 respectively, the rings 29 being loosely engaged with the splines or keys28, while the clutch rings or plates 30 are splined or keyed at 31 and 32 respectively with the overrun clutch gear 20 and the collar .33 fixed to the driving shaft A, the. shell 27 being fitted with a retaining cap 34 for the rings or plates 29 and 30 disposed betweenthe same and the separator disk 26.

The shell 27 has associated or fitted therewith a ball governor including the pivot arms 35 supported upon pivots 36 carriedv by the shell 27, the inner ends or short lengths'of these arms 35 play against a follower 37 within the shell and splined thereto by the splines or keys 28 to act against the clutch rings or plates 29 and 30. The long lengths of the arms 36 at their free ends have ball weights 38 and the jaws 39 working against coiled tensioned springs 40.

seated at 41 against the shell 27, these springs being designed to normally hold the wei ht arms 35 inwardly close to the driven shaft B and the tension of these springs is overcome by centrifugal force for the automatic outward swinging of the arms 35 with the ball weights 38 for the operation of the governor to close the friction clutch.

. The shell 27 is fixedly splined or keyed to the driven shaft B for rotation therewith.

In the operation of the speed changing mechanism or automatic transmission upon rotation of the driving shaft A its power is transmitted through the sleeve hub 19 of the sun gear 18 meshing with the planetary gears 15 of the spider 13 fixed to said shaft to the separator disk 26 and shell 27 to the driven shaft 13, that is, when the speed of rotation of said shaft A .is low and upon an increase of speed of the said driving shaft beyond that of the driven shaft B through the ratio of the planet gears 15 and the sun gear 18 and overrun clutch gear 20, the latter will be caused to reversely travel and lock with the overrun clutch member 24 fixed in the casing 12 which is stationary and through centrifugal action the governor by its weighted arm 35wvill be actuatedto close the friction clutch, thus coupling the driven shaft B with the'driving shaft for the transmission of its speed or travel through the wheel 33 and said friction clutch directly to the shaft B and thus cause the speed of the driven shaft togradually increasev to that of the driving shaft A. When the shaft B. The ratio of the speed of'the driv-- ing shaft A to that of the driven shaft B depends only upon the ratio of the planet gears 15, sun gear 18 and overrun clutch gear 20, thus it being seen that speed change from the driving to the driven shafts A and B takes place automatically so that the change takes place from a low to a high gear ratio during the movement of' the motor driven vehicle and the operation of the shift lever of the transmission gearing ordinarily employed in such vehicle is only required to place the gearing into forward, neutral and reverse positions.

It is of course understood that by the usual acceleration the speed of the driving shaft A can be regulated and the planetary action with the overrun clutch in association with the ball governor friction clutch effects the automatic speed changing from low to high or vice versa between'the driving and driven shafts A and Ba. thereby eliminating the manual shift of transmission gearing and the use of an intermediate speed change as is common in theemployment of hand controlled transmission gearing employed in motor driven vehicles.

What is claimed is 1. In an automatic gear shift, driving and driven shafts, planetary gear assembly connected with the driving-shaft, a sun gear loose upon the driving shaft and in mesh with the planetary gear assembly and having a sleeve hub, anoverrun clutch having a clutch gear about said sleeve hub and meshing with theplanetary gear assembly, a friction clutch carried by the driven shaft and having clutch rings loosely keyed with the overrun clutch gear and with the driving shaft, and a ball: governor operative upon the friction clutch for the automatic opening and closing thereof by variance in speed ratio of the driving and driven shafts. q 2. In an automatic gear shift, driving and driven shafts, planetary gear assembly connected with the driving shaft, a sun gear loose upon the driving shaft and in mesh with the planetary gear assembly and hav 'ing a sleeve hub, an overrunclutch having a clutch gear about said sleeve hub and meshing with the planetary gear assembly, a friction clutch carried by the driven shaft and having clutch rings loosely keyed with the overrun clutch gear and with the driving shaft, a ball governor operative upon the friction clutch for the automatic opening and closing thereof by variance in speed ratio of the driving and driven shafts, and

a stationary casing inclosin the planetary gear assembly, overrun and 'ction clutches and supporting the said overrlm clutch.

' 3. In an automatic gear shift, driving and driven shafts, planetary gear assenibly connected with the driving shaft an overrun clutch operatedby said bly, a friction clutch connected with the driven shaft and coacting with the overrun clutch, a ball gov ernor active upon the friction clutch and operative by speed ratio between the driving and driven shafts, astationary casing inclosing the planetary qlear assembly, overrun and friction clutc es and support said overrun clutch, a sun gear meshing wit the planetary gear assembly and associated with the friction clutch, and an overrun clutch gear meshing with the planetary gear assembly and associated with said friction clutch.

In testimony whereof I my signature. I

i J OHN C. STAFFORD. 

